Ruiko Saten (佐天 涙子 Saten Ruiko) is a character from the Toaru Kagaku no Railgun sidestories and is one of the main characters of the series. She is a Level 0 esper in Academy City and is both the classmate and best friend of Kazari Uiharu. She is voiced by Kanae Ito in the Japanese Dub and Brina Palencia in the English Dub.